All of these nations were notable nation-states for at least several decades (in some cases several centuries) before the German nation finally achieved unification in 1871. Interestingly, 1871 is also the year many historians point to for Italian unification.

Italian and German unification were both protracted processes that involved the unification of disparate kingdoms, principalities, and republics united only by a shared language and a somewhat-common history. The process began, in both countries, earlier in the nineteenth century, and culminated in 1871. 

During the rise of nationalism in Europe—a process begun around the sixteenth century and culminating in the World Wars of the twentieth century—the most important factor for determining shared national identity was a shared language. This is how German nationality arose from the scatterings of Germanic people around Europe—they often spoke the same root language. The same is true in Italy, France, England, and so on.

Camillo di Cavour was chosen as the Prime Minister of the Kingdom of Piedmont-Sardinia (in Northern Italy) by the King Victor Emmanuel II in 1852. Cavour was a dedicated statesman who used his position to push for economic expansion and, subsequently, the political expansion of his kingdom. By 1871, Italian unification had been achieved.

When trying to answer this question, it is first useful to know what a nation-state is. A state is a political entity, whereas a nation is a cultural or ethnic identity. So, Basque might be a nation in Spain, but Spain is the state that Basque is within. In Europe throughout the late Medieval period, the Renaissance, and the Enlightenment, nation-states began to emerge. Nation-states are political bodies unified with a cultural or ethnic identity. They primarily emerged in countries like England, France, Spain, the Netherlands, and Sweden in the early Renaissance period, and this system of nation-states was then exported around the world as the Western European powers continued to expand their influence. It is now the dominant political entity in the world and its significance has not waned in the twentieth or twenty-first centuries.

Throughout most of Europe, from the fall of the Roman Empire until the Renaissance period, only a tiny fraction of people had access to education or any time to devote to scholarly pursuits. Those who did usually wrote in Latin, the language of classical writing, rather than in their local language. In the Renaissance period, the use of Latin was slowly phased out and replaced with the local language, or the “vernacular.” This was very significant because it allowed a great many more people than ever before to read, write, and understand works of literature and nonfiction.

At the beginning of the nineteenth century, each of these nations was either a part of a larger empire or split into many different kingdoms and republics except for Russia, which already had a centralized government that reflected the people of the same nation.

The commercial revolution began in Amsterdam, but it would never have been able to do so without the Thirty Years’ War and the Peace of Westphalia, which ended that war. The Netherlands, previously under Spanish dominion, became independent; the country was then free to follow its own path of Protestantism and vigorous free market capitalism.

Theodor Herzl is most famous for his advocation of a Jewish homeland in an essay called Der Judenstaat. In it, he argued that the only way to end European persecution of Jews was to give the Jewish people their own homeland. This was the beginning of the Zionist movement that was given greater emphasis by the Balfour Proclamation in 1917 and that resulted in the establishment of Israel in 1948.

The Magna Carta is often referenced as the beginning of British, and therefore American, democracy. It created a Great Council of Lords and Barons with whom the King had to consult before making any significant decisions. This is clearly hardly democracy— it's more like an oligarchy—but this council would one day evolve into the British Parliament, from which true democracy would eventually flow. The signing of the Magna Carta is also significant in that it may be seen as the very beginning of the English nation-state. It is a foundational legend upon which the British government and people can trace their shared history and legitimacy back eight hundred years.